Ionic conductivity of unsaturated polyester resin networks containing LiCIO4

Abstract

Poly(ethylene oxide) (PEO) 400‐maleate‐isophthalate resins have been prepared and LiCIO₄ dissolved in the resins before crosslinking with 30% of styrene, vinylpyrrolidone or vinylpyridine. The DC conductivities of the resins were measured and found to increase in the order vinylpyridine 〈vinylpyrrolidone〉 styrene for the same [EO]/[Li⁺] ratio ( = 50). For the styrene system σ = 3 × 10⁻⁶Scm⁻¹ at ambient temperatures and for the vinylpyridine system σ = 1 × 10⁻⁷ Scm⁻¹. The T_gs of the system were also measured using dynamic mechanical thermal analysis and were found to be very close (257‐260 K). The above sequence was therefore attributed to stronger site‐binding of lithium ions at the more polar comonomers. An interpenetrating network (IPN) consisting of the styrene‐polyester and incorporating 40% PEO 400 was also prepared with[EO]/[Li⁺]ratios of 20 and 50. These gave ambient temperature conductivities of 1 × 10⁻⁵ and 3 × 10⁻⁵ Scm⁻¹, respectively.